The seminal achievement of the paleomagnetic community over the last half-century was the successful reconstruction of 300 million years of reversal history of the Earth’s magnetic field. This paleomagnetic timescale continues to be helpful to geophysicists studying plate tectonics, paleontologists studying evolution, stratigraphers studying basin development, and even magneto-hydrodynamic modelers trying to reproduce aspects of geomagnetic field behavior. However, this timescale covers only 7% of the Earth’s past, as typical magnetic recorders, such as lava flows and limestone, become progressively more rare and mineralogically altered with age.

This talk will introduce the audience to a new geologic material, magnetic inclusions in silicates, which is allowing researchers to investigate the behavior of early Earth’s magnetic field. Magnetic inclusions are found in many of the most common minerals as well as in meteorites. The silicate hosts protect the magnetic inclusions from alteration during variations in temperature, pressure, chemical environment, and redox state caused by common geologic processes such as metamorphism and weathering. Paleomagnetic studies of single crystals containing these inclusions are progressively revealing the remaining 93% of Earth’s geomagnetic history to the scientific community.